1. Field of the Invention
The present invention relates generally to an apparatus and method for tuning a string musical instrument and more particularly to an apparatus and method for tuning acoustical and electric guitars, wherein an adjustable bridge is used in combination with an adjustable nut to provide a perfectly tuned guitar.
2. Description of the Prior Art
The electrical guitar of today is far different from its early counterpart which was conceived approximately some forty years ago. Changes have been relatively slow in coming in the art when considering that today's guitar can not be perfectly tuned. As an example, the foundations for the modern concept of intervals were laid by the Greek scientist Pythagoras in the 6th century B.C. A combination of today's technology and very demanding players has made it necessary to vastly improve and refine all aspects of string instruments to better suit their needs.
Guitar tuning is based on the equal-tempered scale, in which the ratio of each successive semitone to the next is based on the twelfth root of two. The octave is divided into twelve equal semitones, and to achieve this end the frets must be precisely placed. The twelfth root of two equals 1.0594631 (correct to seven places) and it is this ratio of 1.0594631:1 which is used as the basis for computing semitone intervals in equal-tempered tuning.
Simply stated, the ratio 17:18, own as the "eighteen rule", indicates that if a selected string length is divided into eighteen parts the distance from the saddle of the bridge to the first fret will equal seventeen parts. The distance from the nut to the first fret will equal 1/18 of the string or scale length. If the remaining distance is again divided into eighteen parts, 1/18 of that distance will be the interval between the first and second frets. By continuing on for each fret, the fret positions for the entire fingerboard can be laid out.
However, it is well known in the art that with the placement of the frets, as indicated above, it is still not possible to perfectly tune classical guitars, acoustic guitars or electric guitars, wherein all the strings will play in perfect harmony. This will be discussed in more detail in the following description.
The length of each string is now adjustable between the bridge and the fixed nut. This has been brought about by the use of an adjustable bridge device, wherein the bridge is provided with adjustable saddles on which the strings rest. This then, establishes a means for allowing each string to be adjustably compensated at the bridge saddle according to it's length, tension, mass per unit length (diameter), and material that comprises the string. (See Physics For Scientist & Engineers, 2nd Edition, Chapters 18.1-18.4). That is, one can set the length of each string by adjusting the respective saddle that the string engages so as to establish a set length for its particular harmonic value. However, it is important to understand that it has been found that the lengthening or the shortening of the strings by means of an adjustable bridge does not affect in a positive manner the acoustics of a tone or sound (which is determined by the frequency of the vibration of the sound waves reaching the ears) for that portion of each respective string between the twelfth fret and the first fret and its respective interval. In other words, only the twelfth fret and the intervening frets and intervals located between the adjusted saddles of the bridge and the twelfth fret are affected in a positive manner. The length of each string only changes between the fixed nut and the adjustable saddle, and thus the longitudinal position of the strings does not change with respect to the fixed position of the nut and the first fret and the intervening frets, and intervals located between the fixed nut and the twelfth fret.. And, oddly enough, therein lies the problem which has been solved by the present invention after long and tedious research. Until now the strings of a guitar have only been adjusted for a given length in one direction, whereby the length of each string is defined between the fixed nut and the bridge.
It is important that it be stressed that, until now, there has been no indication that anyone skilled in the art has given any consideration to adjusting both the nut end and the bridge end of each string. Accordingly, the dual end adjustment of the strings, as disclosed herein, allows for the first time a defined length of string to be positioned longitudinally relative to the fixed frets and their corresponding intervals. The need for longitudinally shifting the location of each individual string relative to the fixed frets along the neck of a guitar has not been recognized or even considered in the known art. As long as the strings are fixed at the nut, even though they are adjustable at the bridge, they are not capable of being selectively positioned longitudinally along the neck of the guitar so as to correspond to the position of the frets, particularly with respect to the first and twelfth intervals.
The chords in the first position, especially E, D, C, and G will sound out of tune when played. Any guitar in current use that employs a fixed straight nut, no matter how expensive the guitar might be, cannot play the first interval correctly and will therefore be out of tune. This is true no matter which one of the many tuning methods might be employed by the player.
It is important to note that an equal-tempered tuning method is the basic system used because most, if not all, electric guitars are constructed to play in equal temperament. This means that perfect intervals and chords in all keys are an impossibility with what is available in the art today.
Most, if not all, guitar players prefer that their instruments intonate correctly, that is to say, that their guitars play equally in tune at all points on the keyboard (fingerboard). However, no existing adjustable bridge alone can possibly achieve such a setting. Moreover, adjustable bridges that are in use today cannot correctly adjust string intonation.
All adjustable bridges set intonation by lengthening or shortening each string so as to align the string for it can intonate correctly on its corresponding octave on the twelfth fret. Although this will closely intonate strings from the twelfth fret to the bridge, it has little or no affect on strings closer to the fixed nut which is the most often played area of the instrument.
Until late in this century, the tuning of a string instrument was not given any serious thought and thus the principle concept of tuning a guitar has been almost solely directed to employing an adjustable bridge device as previously described. Virtually every aspect of the electric guitar has been improved and upgraded by present technology standards from various body materials to state of the art electronics and ergonomic contours. Yet the fretboard and its interval design has remained the same, notwithstanding material improvements only.
There are many arrangements of adjustable bridge devices which one can find in the following U.S. Patents:
______________________________________ Pat. No. 2,740,313 to Pat. No. 4,236,433 to T. M. McCarty Stephen Holland Pat. No. 4,281,576 to Pat. No. 4,373,417 to C. Leo Fender Gregg Wilson et al Pat. No. 4,541,320 to Pat. No. 4,867,031 to Michael N. Sciuto C. Leo Fender ______________________________________
All of the above patents as well as all instruction books from how to play a guitar to how to tune a guitar have never mentioned or even suggested the incorporation of the present device as herein described and claimed.